In a statement, the partner, Michael Goguen, said the departure would allow him to focus on clearing his name after a relationship ended badly.

Sequoia, one of the earliest U.S. venture capital firms, and Goguen said that the lawsuit had no relation to the firm.

"We understand that these allegations of serious improprieties are unproven and unrelated to Sequoia," a Sequoia spokesman said in a emailed statement. "Nevertheless, we came to the decision that Mike's departure was the appropriate course of action."

The firm first learned of the claims on Thursday, the spokesman said.

A lawsuit filed March 8 in San Mateo County Superior Court in California claims Goguen abused Amber Laurel Baptiste "sexually, physically and emotionally for over 13 years."

Goguen signed a contract to pay Baptiste $40 million (28 million pounds) as compensation, but after paying her $10 million, Goguen refused to honour the rest of his agreement, according to the lawsuit.

In a statement sent by his law firm, Goguen said the matter was purely personal, with no connection to Sequoia, and that he would file a cross complaint on Monday.

According to his LinkedIn page, Goguen has been leading Sequoia's investments in about a dozen companies.

(Reporting by Lewis Krauskopf in New York; Editing by Mary Milliken and Savio D'Souza)