BEIJING (Reuters) - The Beijing Olympics should still make a profit despite a 30 percent rise in costs since the Chinese capital won the right to host the Games in 2001, according to a senior adviser to the organizers.

Wei Jizhong, who was a member of the bid committee and now advises the Beijing Organizing Committee for Olympic Games (BOCOG), said the rise from the original estimate of $1.65 billion to the anticipated costs of $2.1 billion was "normal."

"I believe the Beijing Olympics will hopefully still be able to make a surplus though the budget necessarily increases," he wrote in Titan Sports newspaper.

"In previous Games, the preliminary budgets tended to be conservative and the actual expenses were all inflated.

"An overspend of about 30 percent is normal. It's because of the more requests from the International Olympic Committee (IOC) and a lot of unpredictable factors. Beijing is not an exception."

The IOC contribute about half of the costs of running the Games and Beijing's three-tiered sponsorship program -- the most comprehensive in the history of the Games, according to BOCOG -- is likely to more than cover the rest.

Organizers and sponsors have been tight-lipped about revenue from the program but sports manufacturer Adidas last month announced they would be paying 100 million pounds ($201.8 million) to be a top tier sponsor for 2012 London Games.

"BOCOG's marketing income will obviously be more than $1 billion," Wei wrote.

Organizers made some alterations to the showpiece National Stadium in 2005 to cut costs and hope to be able to provide security for a third of the $1.8 billion it cost Athens when the Greek capital hosted the last Summer Games in 2004.

Higher levels of security, technological developments, rising prices, exchange rates and the growing cost of human resources were among the factors that caused costs to rise, Wei wrote.

"In one word, some increase in the budget is unavoidable," he wrote.

"But along with an increase in marketing income, some of its effect could also produce profit and the budget increase is still under strict control, within the guideline of frugal Olympics."

"I think the people can put their hearts at ease."

The $2.1 billion estimated bill does not, however, include the estimated $35-40 billion Beijing is spending on upgrading the city's infrastructure and improving the environment.

($1=.4955 Pound)