TOKYO (Reuters) - Sharp Corp rejected an offer by Samsung Electronics Co. to buy its copier and printer unit as part of a deal that will see Samsung invest $110 million in return for a 3 percent stake.

"We did get a proposal from Samsung, but we declined," said Sharp spokeswoman Miyuki Nakayama. She would not say how much Samsung offered and why Sharp refused.

Sharp needs to repay a $2.1 billion convertible bond due in September and selling the profitable copier business would help raise cash, but it would also diminish the company's cashflow.

The copier unit manufactures photocopiers, printers and fax machines for offices.

Sharp in December won an agreement from Qualcomm to invest as much as $120 million. Analysts expect the company to resort to fresh equity financing to bolster its cash reserves before September.

(Reporting by Tim Kelly; editing by Miral Fahmy)