HANOI, May 22 (Reuters) - Vietnam's State Treasury raised 5.12 trillion dong ($201 million) in an auction of 9.5 trillion dong of government bonds at the Hanoi Stock Exchange on Wednesday, with coupons hitting fresh highs this year.

The amount is lower than the $265.5 million raised last week, a bourse filing showed. The uptake was also lower, with only 54% of the offer sold, down from 68% in last week's auction.

The Southeast Asian country is aiming to raise 400 trillion dong from government bond sales this year mainly to fund its public investments, one of the key drivers of economic growth.

The State Treasury sold all of the 2 trillion dong of 5-year bonds offered on Wednesday with a coupon of 1.75%.

It sold 2.2 trillion out of 3 trillion dong of 10-year bonds offered with a coupon of 2.66%. The coupons were 1.72% and 2.61% last week, respectively.

On longer-term bonds, it sold 200 billion dong out of 2 trillion dong of 15-year bonds offered with a coupon of 2.83%, and 719 billion dong out of 1 trillion dong of 30-year bonds offered with a coupon of 3.06%.

It failed to sell any of the 500 billion dong of 20-year bonds offered.

Vietnam has so far this year raised 126 trillion dong from government bond sales, according to data from the exchange.

Companies in Vietnam raised 51.2 trillion dong from corporate bond issuances in the year to May 17, according to data from the Vietnam Bond Market Association. (Reporting by Khanh Vu; Editing by Muralikumar Anantharaman and Sonali Paul)