Fahmi Fadzil said he tweeted in January that a pregnant friend of his had been treated badly by her employers at Female Magazine, owned by Blu Inc Media.
The magazine's lawyers threatened legal action and a settlement was reached in March, taking the resolution to the Internet because Fahmi could not afford to take out newspaper advertisements.
"The only demand is to tweet the apology 100 times for three days, and that will be the final and full settlement of this," Fahmi told AFP.
He began tweeting "I've DEFAMED Blu Inc Media & Female Magazine. My tweets on their HR Policies are untrue. I retract those words & hereby apologise" on Thursday morning.
"Under the settlement, I have been ordered to tweet the apology over the next three days and that works out to about one apology tweet every 35 minutes, and I will finish the tweets by 6:45pm on Saturday," he said.
"So far, I have finished 13 tweets and have 87 more to go," he added. His Twitter feed is at fahmi_fadzil.
Fahmi's lawyer Syahredzan Johan said the settlement requiring statements on Twitter was the first of its kind in Malaysia.
"In terms of defamation, we are definitely entering uncharted waters," he said.
"In terms of blogging, there have been cases of apologies on the net but this is the first of its kind in Malaysia in terms of tweeting an apology," Syahredzan added.
"The only reason why this (Twitter apology) came about was because both parties agreed to it. At least this allows for a form of settlement -- at least this is a way out."
Malaysians are avid users of social network and micro-blogging sites.
A study by global research firm TNS last year showed Malaysians to be the most popular people on the Internet, with an average of 233 friends in their social networks compared with 68 in China and just 29 in Japan.
COMMENTS
Comments are moderated and generally will be posted if they are on-topic and not abusive.
For more information, please see our Comments FAQ