CHICAGO (Reuters) - Discount retailer Family Dollar Stores Inc (>> Family Dollar Stores, Inc.), which is trying to ward off a hostile bid from rival Dollar General Corp (>> Dollar General Corp.), said its fourth-quarter profit slid 66 percent hurt by inventory markdowns, restructuring charges and merger fees.

Family Dollar, which has agreed to sell itself to smaller rival Dollar Tree (>> Dollar Tree, Inc.) for a lower cash-and-stock deal of $8.5 billion, rejected Dollar General's $9.1 billion all-cash bid saying the offer did not address anti-trust concerns.

After being spurned twice, Dollar General, which offered to sell up to 1,500 stores and pay $500 million as a break-up fee if the deal failed to clear antitrust reviews, took its bid hostile and approached Family Dollar shareholders directly.

The company did not comment on its merger plans in its earnings conference call on Thursday. On Oct. 1, Dollar General extended its tender offer to acquire Family Dollar shares for $80 a piece from Oct. 8 to end of this month.

The battle in the discount retail industry comes at a time when Dollar stores are desperate to scale up as they try to keep lower-income shoppers from being lured by Wal-Mart Stores Inc (>> Wal-Mart Stores, Inc.) and Target Corp (>> Target Corporation).

Family Dollar, which did not provide guidance for fiscal 2015 pending its merger with Dollar Tree, said the company's first quarter in fiscal 2015 will be challenging due to competitive intensity and as low-income customers continue to be wary of spending.

Net income for the fourth quarter ended Aug. 30 fell 66 percent to $34.5 million, or 30 cents per share from $102.2 million, or 88 cents per share, a year earlier. Excluding items, earnings were 73 cents per share from 86 cents per share.

Family Dollar had $10.4 million in inventory write-downs, as it shut 375 stores during the quarter. It also had $55.2 million in restructuring charges as part of its planned store closures and $9.4 million in expenses related to its pending merger.

Selling, general and administrative expenses, as a percentage of net sales, were 28.9 percent in the fourth quarter from 28.5 percent a year earlier.

The company, which operates over 8,000 stores in 46 states, said net sales rose 4.5 percent to $2.61 billion. Same-store sales rose 0.3 percent, after three straight quarters of decline driven by an increase in average customer transaction value which offset a decline in transactions.

Chairman and Chief Executive Howard Levine said the company anticipated the first quarter in fiscal 2015 to be the most challenging next year.

"Our core customer is struggling ... We think it will be a very competitive holiday season," he said in an earnings conference call.

As per the latest filings, Howard Levine, is the largest shareholder with an 8.17 percent stake as of Aug. 5. Any deal could fetch him between $690 million and $750 million.

Nelson Peltz's Trian Fund Management L.P. had a 7.34 percent stake in Family Dollar as of July 27, while John Paulson's Paulson & Co Inc reported a 7.04 percent stake on June 30.

Family Dollar shares ended up slightly at $77.75 on the New York Stock Exchange on Thursday.

(Reporting by Nandita Bose, editing by Chizu Nomiyama)

By Nandita Bose