NEW YORK (Reuters) - Top Office Depot Inc (>> Office Depot Inc) investor Starboard Value LP sued the second-largest U.S. office supply retailer on Thursday for not holding an annual shareholder meeting to elect directors, an unusual step on the eve of a merger.

The activist investor said in the complaint the company had not held an annual shareholder meeting for 13 months. The complaint was filed with the Court of Chancery in Delaware, where Office Depot is incorporated.

Starboard has nominated six members, including former Home Depot CEO Robert Nardelli, for the 10-member Office Depot board. The investor cited the lack of retail experience among current board members and stressed the need to reconstitute the board whether or not its proposed merger with smaller rival OfficeMax Inc (>> OfficeMax Inc) takes place.

"The proposed merger provides no basis for the company to deprive stockholders of their right to meet annually to elect directors," Starboard said in the complaint, dated June 12.

Boca Raton, Florida-based Office Depot revealed plans in February to buy OfficeMax in an all-stock deal worth $937.2 million. They have not yet decided on the combined entity's name, headquarters or CEO.

The companies are awaiting regulatory approval. They will both hold special shareholder meetings separately on July 10 to seek investor approval.

Starboard said it was forced to take the latest action as it did not expect directors to be elected at the special meeting.

Starboard said in its most recent regulatory filing that it held about 42 million shares of Office Depot, or about 15 percent of the company's stock.

Office Depot did not immediately return a call for comment.

(Reporting By Dhanya Skariachan. Editing by Andre Grenon)

By Dhanya Skariachan

Stocks treated in this article : OfficeMax Inc, Office Depot Inc