(Reuters) - Chinese cellphone chip designer Spreadtrum Communications Inc (>> Spreadtrum Communications, Inc (ADR)) will be acquired by a unit of government-owned Tsinghua Holdings Co Ltd for a raised offer price of about $1.78 billion.

Tsinghua Unigroup will pay $31 for each Spreadtrum American Depositary Share (ADS), up from its previous offer of $28.50 per ADS, the companies said on Friday.

The offer represents a premium of 17 percent to Spreadtrum's Thursday closing price on the Nasdaq. Spreadtrum shares were up 12.5 percent at $29.75 in premarket trading on Friday.

Spreadtrum develops chips for smartphones, feature phones and other consumer electronics products. Its chips support 2G, 3G and 4G wireless communications standards.

The company, which gets most of its sales from China and Korea, counts HTC Corp (>> HTC Corp) and Samsung Electronics (>> Samsung Electronics Co., Ltd.) among its customers and had $720 million in revenue last year.

Tsinghua Unigroup will offer Spreadtrum expertise in consumer products, protection and support of a vast IP portfolio, and access to important capital markets in China, Tsinghua Unigroup's Chief Executive Zhao Weiguo said.

Tsinghua Holdings is a Chinese government-owned corporation funded by Tsinghua University and controls companies such as Chengzhi Shareholding Co Ltd (>> Chengzhi Co., Ltd) and technology firm Unisplendour Co Ltd <000938.SZ>.

Spreadtrum said it expects to hold a special meeting of its shareholders to consider the proposed deal.

Spreadtrum, which has a market cap of $1.28 billion, said in June it had received a $1.38 billion buyout proposal from Tsinghua, and was evaluating it.

Morgan Stanley Asia gave fairness opinion to Spreadtrum and Fenwick & West LLP provided legal advice. Morrison and Foerster LLP gave legal advice to Tsinghua.

Spreadtrum's shares have risen 18.6 percent since it received the offer in June. They closed at $26.45 on the Nasdaq on Thursday.

(Reporting by Sruthi Ramakrishnan in Bangalore; Editing by Sreejiraj Eluvangal)